U.S. patent application number 16/447976 was filed with the patent office on 2019-12-26 for optical sensing module.
The applicant listed for this patent is SensorTek technology Corp.. Invention is credited to Feng-Jung Hsu.
Application Number | 20190391008 16/447976 |
Document ID | / |
Family ID | 68968501 |
Filed Date | 2019-12-26 |
United States Patent
Application |
20190391008 |
Kind Code |
A1 |
Hsu; Feng-Jung |
December 26, 2019 |
Optical Sensing Module
Abstract
An optical sensing module for an electronic device is provided.
The electronic device includes an opaque layer and an aperture
formed on the opaque layer, wherein the optical sensing module
includes an optical sensor; a light guide element, disposed between
the opaque layer and the optical sensor and configured to guide
light to the optical sensor through the aperture; and a diffusing
layer, disposed between the opaque layer and the light guide
element, configured to diffuse the light to the light guide
element.
Inventors: |
Hsu; Feng-Jung; (HSINCHU
COUNTY, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SensorTek technology Corp. |
HSINCHU COUNTY |
|
TW |
|
|
Family ID: |
68968501 |
Appl. No.: |
16/447976 |
Filed: |
June 21, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62687819 |
Jun 21, 2018 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01J 1/0437 20130101;
G01J 1/4204 20130101; G02B 6/4298 20130101; G01J 1/0403 20130101;
G02B 5/0278 20130101; G01J 1/0228 20130101; H05K 2201/0108
20130101; G01J 1/0266 20130101; H05K 2201/10121 20130101; H05K
1/0274 20130101; G01J 1/0474 20130101; G02B 6/0011 20130101 |
International
Class: |
G01J 1/04 20060101
G01J001/04; H05K 1/02 20060101 H05K001/02; G01J 1/02 20060101
G01J001/02; F21V 8/00 20060101 F21V008/00 |
Claims
1. An optical sensing module for an electronic device, the
electronic device comprising an opaque layer and an aperture formed
on the opaque layer, wherein the optical sensing module comprises:
an optical sensor; a light guide element, disposed between the
opaque layer and the optical sensor and configured to guide light
to the optical sensor through the aperture; and a diffusing layer,
disposed between the opaque layer and the light guide element,
configured to diffuse the light to the light guide element.
2. The optical sensing module of claim 1, wherein the diffusing
layer is a structural diffusion structure.
3. The optical sensing module of claim 2, wherein the structural
diffusion structure is a non-planar structure processed or formed
by atomization.
4. The optical sensing module of claim 1, wherein the diffusing
layer has a coated particle diffusion structure.
5. The optical sensing module of claim 4, wherein the coated
particle diffusion structure is a transparent light guide film
formed by a coating or particles.
6. The optical sensing module of claim 1, wherein the light guide
element is a light guide column composed of transparent
material.
7. The optical sensing module of claim 1, wherein the light guide
element is composed of a cavity surrounded by a light reflective
layer.
8. The optical sensing module of claim 1, wherein the optical
sensor includes an optical sensor emitter and an optical sensor
detector.
9. The optical sensing module of claim 8, wherein the light guide
element includes an opaque partition to separate the light guide
element into a light guide emitter and a light guide detector.
10. The optical sensing module of claim 1, wherein the aperture is
defined by ink, or the aperture is composed of transparent
material.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional
application No. 62/687,819, filed on 2018 Jun. 21 and included
herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to an optical sensing module,
and more particularly, to an optical sensing module capable of
maintaining a broad field of view (FOV) range.
2. Description of the Prior Art
[0003] With recent technological advancements, display panels of
consumer electronic products are maximized to increase the overall
coverage percentage, thereby achieving a full display. A
characteristic of the full display is that the rim of the display
panel is minimized for greater attractiveness. In order to achieve
this goal, however, an aperture of a conventional optical sensing
device of the display panel needs to be shrunk, or the conventional
optical sensing device needs to be disposed at a deeper position
within the electronic product. Under these situations, a range of
the field of view (FOV) of the optical sensing module is limited
and the sensing efficiency is decreased, since a light detecting
channel becomes too narrow and long. Although prior arts utilize a
diffusing structure to increase the FOV range, a penetration rate
of the light is significantly decreased and cannot be transmitted
to a deeper place within the structure after the light passes
through the diffusing structure, which decreases a sensitivity of
the optical sensing module. Therefore, an improvement to the
conventional technique is necessary.
SUMMARY OF THE INVENTION
[0004] In order to solve the above mentioned problems, the present
invention provides an optical sensing module capable of maintaining
a broad FOV range when applied to a deeper structure or one with a
smaller aperture.
[0005] In an aspect, the present invention discloses an optical
sensing module for an electronic device, wherein the electronic
device includes an opaque layer and an aperture formed on the
opaque layer, and the optical sensing module comprises: an optical
sensor; a light guide element, disposed between the opaque layer
and the optical sensor and configured to guide light to the optical
sensor through the aperture; and a diffusing layer, disposed
between the opaque layer and the light guide element, configured to
diffuse the light to the light guide element.
[0006] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic diagram of an optical sensing module
according to an embodiment of the present invention.
[0008] FIG. 2 is a comparison schematic diagram between a field of
view range and an energy strength of an optical sensor when an
optical sensing module according to an embodiment of the present
invention and a conventional optical sensing module are applied on
a structure with a smaller aperture and shallower depth.
[0009] FIG. 3 is a comparison schematic diagram between a field of
view range and an energy strength of an optical sensor when an
optical sensing module according to an embodiment of the present
invention and a conventional optical sensing module are applied on
a structure with a smaller aperture and shallower depth.
[0010] FIG. 4 is a comparison schematic diagram between a field of
view range and an energy strength of an optical sensor when an
optical sensing module according to an embodiment of the present
invention and two different conventional optical sensing modules
are applied on a structure with a smaller aperture and shallower
depth.
[0011] FIG. 5 is a schematic diagram of another optical sensing
module according to an embodiment of the present invention.
[0012] FIG. 6 is a schematic diagram of another optical sensing
module according to an embodiment of the present invention.
[0013] FIG. 7 is a schematic diagram of another optical sensing
module according to an embodiment of the present invention.
[0014] FIG. 8 is a schematic diagram of another optical sensing
module according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0015] Refer to FIG. 1, which is a schematic diagram of an optical
sensing module 10 according to an embodiment of the present
invention. The optical sensing module 10 includes an optical sensor
104, a light guide element 108 and a diffusing layer 110. The
optical sensing module 10 may be applied on an electronic device,
which includes an opaque layer 102 and an aperture 106 formed on
the opaque layer 102 configured to guide light in and out of the
aperture 106. For example, the aperture 106 may be defined by ink.
The opaque layer 102 is coated with the ink to block the light, and
the region without the ink may be the aperture 106, or the aperture
106 may be glass, plastic plate or other transparent materials
disposed on the opaque layer 102. The light guide element 108 is
disposed between the opaque layer 102 and the optical sensor 104,
and configured to guide the light to the optical sensor 104 through
the aperture 106. The diffusing layer 110 may be a structural
diffusion structure or a coated particle diffusion structure,
disposed between the opaque layer 102 and the light guide element
108, for diffusing the light into the light guide element 108, such
that the light is more uniform. For example, the diffusing layer
110 may be composed of the light guide element 108, which is close
to a top surface of the opaque layer 102, i.e. the top surface of
the light guide element 108 is processed by atomization or formed
by a non-planar structure, so as to guide the diffused light to the
light guide element 108 after the diffused light enters the optical
sensing module 10. Alternatively, the diffusing layer 110 may be a
transparent light guide film formed via a coating or particles,
disposed between the opaque layer 102 and the light guide element
108 to guide the diffused light to the light guide element 108
after the diffused light enters the optical sensing module 10.
Therefore, the optical sensing module 10 of the present invention
utilizes the uniformly diffusing structure of the diffusing layer
110 to uniformly guide light to the light guide element 108. The
light guide element 108 collects the light to the optical sensor
104 to obtain a better field of view (FOV) and sensing
efficiency.
[0016] In detail, the aperture 106 of the optical sensing module 10
has a diameter W1 and the optical sensor 104 has a depth D1. When
the diameter W1 of the aperture 106 is smaller or the depth D1 is
larger, a range of the FOV of the optical sensing module 10 becomes
smaller, making it difficult to transmit light to the optical
sensor 104. When the optical sensing module 10 of the present
invention is utilized on a deeper structure or one with a smaller
aperture, however, the light is uniformly diffused after entering
the optical sensing module 10 through the diffusing layer 110, such
that the light guide element 108 uniformly collects the light to
the optical sensor 104 to thereby increase the FOV of the optical
sensing module 10, which increases the sensing efficiency of the
optical sensing module 10.
[0017] In an embodiment, the light guide element 108 may be a light
guide column composed of Polycarbonate (PC), Polymethyl
methacrylate (PMMA), glasses or transparent materials. The light
guide element 108 collects the light entering the optical sensing
module 10, which is diffused by the diffusing layer 110 to the
optical sensor 104. In other embodiments, however, the light guide
element 108 may be composed of a cavity surrounded by a light
reflective layer. For example, since the optical sensing module 10
is disposed inside the electronic device in practical applications,
a central part 108a of the light guide element 108 may be the
cavity inside the electronic device, and the central part 108a is
surrounded by a peripheral part 108b of the light guide element
108. The peripheral part 108b may be a light reflective layer
composed of a reflective plate or a reflective coating, such that
the light guide element 108 may collect the light entering the
optical sensing module 10, which is diffused by the diffusing layer
110, and transmit the light to the optical sensor 104.
[0018] Since the diffusing layer 110 is disposed between the opaque
layer 102 and the light guide element 108, in an embodiment, when
the incident light is uniformly diffused by the diffusing layer
110, the light guide element 108 may collect a larger range of
light and further obtain a larger FOV without the alignment with
the aperture 106 or the optical sensor 104. In addition, after the
incident light uniformly passes through the diffusing layer 110,
the light guide element 108 may effectively collect the diffused
light to the optical sensor 104, so as to increase sensitivity of
the optical sensing module 10. In this way, the optical sensing
module of the present invention may be utilized on a deeper
structure and with a smaller aperture to achieve a required broad
FOV, e.g. an ambient light sensor (ALS).
[0019] Refer to FIG. 2, which is a comparison schematic diagram of
the FOV range and energy strength of the optical sensor when the
optical sensing module 10 and a conventional optical sensing module
are applied on a structure, where the diameter W1 of the aperture
106 is 1 mm and the depth D1 is 0.5 mm of the applied structure.
The x-axis in FIG. 2 represents the angle of the FOV and the y-axis
represents a relative energy strength percentage of the light
received by the optical sensor 104. Those skilled in the art may
understand that the relative energy strength percentage is a result
of normalizing the measured energy strength of the light received
by the optical sensor 104 at each angle. In FIG. 2, a solid curve
L1 represents a relationship between the FOV and the energy
strength of an optical sensing module without any light guide
structure and light diffusing structure and a dotted curve L2
represents a relationship between the FOV and the energy strength
of the optical sensing module 10 of the present invention. If the
energy strength 50% is taken as a standard of good sensing of the
optical sensor, when the diameter W1 of the aperture of the applied
structure is smaller (e.g. 1 mm), and the depth D1 of the optical
sensor 104 is shallower (e.g. 0.5 mm), the FOV of the conventional
optical sensing module is within .+-.40 degrees. Comparatively, the
FOV of the optical sensing module 10 according to the embodiment of
the present invention is about .+-.50 degrees. That is, when the
aperture of the applied structure is smaller, the FOV of the
optical sensing module 10 according to the embodiment of the
present invention is larger than that of the conventional optical
sensing module.
[0020] Refer to FIG. 3, which is a comparison schematic diagram of
the FOV range and energy strength of the optical sensor, when the
optical sensing module 10 and a conventional optical sensing module
are applied on a structure, where the diameter W1 of the aperture
106 is 5 mm and the depth D1 is 3.5 mm of the applied structure.
The x-axis of FIG. 3 represents the angle of the FOV and the y-axis
represents a relative energy strength percentage of the light
received by the optical sensor 104. In FIG. 3, a solid line L1
represents a relationship between the FOV and the energy strength
of an optical sensing module without any light guide structure and
light diffusing structure and a dotted curve L2 represents a
relationship between the FOV and the energy strength of the optical
sensing module 10 of the present invention. When the diameter W1 of
the aperture 106 of the applied structure is larger (e.g. 5 mm),
but the depth D1 of the optical sensor 104 of the applied structure
is deeper (e.g. 3.5 mm), the FOV of the conventional optical
sensing module is within .+-.35 degrees. Comparatively, the FOV of
the optical sensing module 10 according to the embodiment of the
present invention is about .+-.50 degrees. That is, when the
optical sensor 104 is applied on the deeper structure, the FOV of
the optical sensing module 10 according to the embodiment of the
present invention is larger than that of the conventional optical
sensing module.
[0021] Refer to FIG. 4, which is a comparison schematic diagram of
the FOV range and energy strength of the optical sensor, when the
optical sensing module 10 according to an embodiment of the present
invention and two different conventional optical sensing modules
are applied on a structure, where the diameter W1 of the aperture
106 is 1 mm and the depth D1 of the applied structure is 3.5 mm.
The x-axis in FIG. 4 represents the angle of the FOV and the y-axis
represents a relative energy strength percentage of the light
received by the optical sensor 104. In FIG. 4, a solid curve L1
represents a relationship between the FOV and the energy strength
of an optical sensing module without any light guide structure and
light diffusing structure, a dotted curve L2 represents a
relationship between the FOV and the energy strength of the optical
sensing module 10 of the present invention, and a short-line curve
L3 represents a relationship between the FOV and the energy
strength of an optical sensing module with a light diffusing
structure but without any light guide structure. When the diameter
W1 of the aperture of the applied structure is smaller (e.g. 1 mm)
and the depth D1 of the optical sensor 104 of the applied structure
is deeper (e.g. 3.5 mm), the FOV of the conventional optical
sensing module without any light guide structure and light
diffusing structure is narrowed down to about .+-.10 degrees. On
the other hand, when the optical sensing module has a light
diffusing structure but no light guide structure, it is noted that
the energy strength received by the optical sensor is significantly
attenuated when the FOV increases, such that the FOV is about
.+-.25 degrees, which negatively affects the sensing efficiency.
Comparatively, the FOV of the optical sensing module 10 according
to the embodiment of the present invention is maintained at about
.+-.60 degrees. In addition, attenuation of the energy strength
received by the optical sensor 104 is relatively moderate when the
FOV increases, which maintains a better FOV and sensing efficiency
of the optical sensing module 10 according to the embodiment of the
present invention.
[0022] As can be known from the above, when the applied structure
of the optical sensing module 10 has a smaller diameter W1 of the
aperture 106 or a deeper depth D1 of the optical sensor 104, the
optical sensing module 10 according to the embodiment of the
present invention may have a larger FOV and higher sensitivity. In
brief, when the applied structure of the optical sensing module 10
has a diameter W1 of the aperture 106 smaller than 5 mm (especially
smaller than 3 mm) or a depth D1 of the optical sensor 104 larger
than 0.5 mm (especially larger than 2 mm), the optical sensing
module 10 according to the embodiment of the present invention may
have better FOV and sensing efficiency than the conventional
sensing modules; when the applied structure of the optical sensing
module 10 has a diameter W1 of the aperture 106 smaller than 1 mm
or a depth D1 of the optical sensor 104 larger than 3.5 mm, the
optical sensing module 10 according to the embodiment of the
present invention may achieve even greater improvement. Hence, the
optical sensing module 10 according to the embodiment of the
present invention maintains better FOV and sensing efficiency
compared to the conventional sensing module, especially for the
applied structure with a smaller diameter W1 of the aperture 106
and a deeper depth D1 of the optical sensor 104. In other words,
referring to defining a width-to-depth ratio R of the diameter W1
of the aperture 106 and the depth D1 of the optical sensor 104, the
optical sensing module 10 according to the embodiment of the
present invention may achieve outstanding improvement when the
width-to-depth ratio R is smaller than or equal to 1.5.
[0023] Notably, the optical sensing module of the present invention
is not limited to the embodiment disclosed in FIG. 1. Refer to FIG.
5 to FIG. 8, which are schematic diagrams of optical sensing
modules 50, 60, 70, 80 according to embodiments of the present
invention. The optical sensing modules 50, 60, 70, 80 of FIG. 5 to
FIG. 8 have similar structures to the optical sensing module 10 in
FIG. 1; therefore, the elements in the optical sensing modules
50-80 having the same function as those in the optical sensing
module 10 are annotated with the same numerals. Compared to FIG. 1,
the optical sensing module 50 of FIG. 5 further includes a
transparent layer 512 disposed above the opaque layer 102, wherein
the transparent layer 512 may be a structure of a panel of the
electronic device, a shell, etc.
[0024] Compared to FIG. 1, the optical sensing module 60 of FIG. 6
further includes a transparent layer 612 disposed above the opaque
layer 102, and the diffusing layer 110 is disposed between the
opaque layer 102 and the light guide element 108. In detail, the
diffusing layer 110 may be adhered to a top surface of the aperture
106 of the opaque layer 102 and is separated by the light guide
element 108.
[0025] Compared to FIG. 1, the optical sensor 104 of the optical
sensing module 70 shown in FIG. 7 may further include an optical
sensor emitter 704E and an optical sensor detector 704D, to
respectively emit sensing light and receive incident light. The
light guide element 108 may include an opaque partition 714, which
divides the light guide element 108 into a light guide emitter 708E
and a light guide detector 708D, to guide the light emitted by the
optical sensor emitter 704E and guide the incident light received
from outside, thereby preventing the light emitted by the optical
sensor emitter 704E from directly affecting the optical sensor
detector 704D. Notably, the diffusing layer 110 of the optical
sensing module 70 may only be disposed on a region corresponding to
the optical sensor detector 704D and the light guide detector 708D
to diffuse the incident light from outside.
[0026] Compared to FIG. 1, the optical sensing module 80 of FIG. 8
further includes a transparent layer 812, an optical sensor emitter
804E and an optical sensor detector 804D. The transparent layer 812
is disposed above the opaque layer 102, and the light guide element
108 may include an opaque partition 814, which divides the light
guide element 108 into a light guide emitter 808E and a light guide
detector 808D. In addition, the diffusing layer 110 of the optical
sensing module 80 is disposed between the opaque layer 102 and the
light guide element 108, wherein the diffusing layer 110 may be
adhered to a top surface of the aperture 106 of the opaque layer
102, and is separated from the light guide element 108. Notably,
the diffusing layer 110 of the optical sensing module 80 may only
be disposed on a region corresponding to the optical sensor
detector 804D and the light guide detector 808D.
[0027] Those skilled in the art may design the optical sensing
module according to different system requirements. For example, a
shape of the light guide element or a material of the diffusing
layer may be modified according to requirements of users or
devices, and is not limited to those shapes and materials described
in the disclosure. Other shapes and materials also fall within the
scope of the present invention.
[0028] In summary, the present invention provides an optical
sensing module capable of maintaining a broad FOV range of the
optical sensing module when the applied structure is deeper or has
a smaller aperture, so as to achieve a function of broad FOV of an
ambient light sensor.
[0029] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *